Rhodium(I) carbonyl complexes of triphenylphosphine chalcogenides and their catalytic activity

Rhodium(I) carbonyl complexes [Rh(CO)(2)ClL] where L = Ph3PO, Ph3PS and Ph3 PSe, were synthesized and characterized by elemental analysis, i.r. and by H-1-, C-13- and P-31-n.m.r. spectroscopy. The nu(CO) band frequencies in th e complexes follow the order: Ph3PO > Ph3PS > Ph3PSe, in keeping with the h ard/soft nature of the interactions. The complexes undergo oxidative additi ons with electrophiles such as MeI, PhCH2Cl and I-2 to give, e.g. [Rh(CO)(C OMe)ClIL] which react with PPh3 to give trans-[Rh(CO)Cl(PPh3)(2)]. The cata lytic activity of the [Rh(CO)(2)ClL] complexes in carbonylation of MeOH is higher than that of the well-known [Rh(CO)(2)I-2](-) species.